A former chairman of the Co-operative Bank has apologised "to all I have hurt or failed by my actions" after it was reported that he has been caught buying and using illegal drugs including crystal meth, crack cocaine and ketamine.

The Mail on Sunday said that the Rev Paul Flowers, a Methodist minister, was filmed buying the substances just days after he was grilled by the Treasury Select Committee over the bank's disastrous performance.

The Rev Flowers, who chaired the Co-operative Banking Group and the Co-operative Bank for three years, issued a statement which said: "This year has been incredibly difficult, with a death in the family and the pressures of my role with the Co-operative Bank.

"At the lowest point in this terrible period, I did things that were stupid and wrong. I am sorry for this and I am seeking professional help, and apologise to all I have hurt or failed by my actions."

A Methodist Church spokesman said: "We expect high standards of our ministers and we have procedures in place for when ministers fail to meet those standards.

"Paul is suspended from duties for a period of three weeks, pending investigations, and will not be available to carry out any ministerial work. We will also work with the police if they feel a crime has been committed."

The Co-op has been trying to plug a £1.5 billion gap in finances which was d iscovered following the purchase of the Britannia Building Society and abortive plans to buy hundreds of Lloyds branches.

The newspaper said that Rev Flowers, 63, is seen in his car in a video discussing the cocaine and crystal meth he wants from a dealer in Leeds.

He reportedly then counts out £300 in £20 notes and sends a friend to make the deal.

The video and a series of text messages were handed to the newspaper by an acquaintance of Rev Flowers who was "disgusted by his hypocrisy", it said.

The text messages prove Rev Flowers, a former Labour councillor, was using hard drugs in the days surrounding his testimony to the Treasury Committee on November 6, it added.

On the day after his appearance at the Commons, he sent a text reading: "I was 'grilled' by the Treasury Select Committee yesterday and afterwards came to Manchester to get wasted with friends."

The newspaper said Rev Flowers, who is gay, also boasts of using illicit substances including ketamine, cannabis and club drug GHB.

Rev Flowers has been a Methodist minister for 40 years, currently in Bradford, and formerly chaired drugs charity Lifeline, it added.

The Co-operative Bank declined to comment.

West Yorkshire Police said they have not received a report in relation to the matter but are aware of the allegations made by the Mail on Sunday newspaper article and are now making inquiries.